This application relates generally to a thin, printable cells and batteries and its manufacturing method. More specifically, this application relates to a thin, printed cell and battery manufactured using a pouch-filling process.
For the past one hundred years or so, scientists have been making Carbon/Zinc portable power sources for various applications. In the early days of portable power, these power sources were very large compared to today's standards. For example the very popular “Ignitor Cell” made by Eveready was about 3″ diameter and about 9″ tall was used in many applications such as radios, buzzers, Xmas lighting. These large cells as well as some smaller versions, such as the Eveready famous #6 (about 2″ dia.×6″ tall) and the smallest unit cell of the day, the #950 (D size) were commonly made into battery packs with voltages exceeding 40 volts in some applications. These were similar in size and larger than today's car batteries, for uses in lighting devices, radios and car ignition systems. In the mid 1900's with the advent of advanced electronics such as the transistor, the electrical requirements for portable power sources were reduced. Consequently cell sizes were also reduced to include C's, AA's, and AAA's and even small button cells. This power reduction has continued into the twenty first century where applications such as smart labels, smart credit cards, sensors, novelty devices such as greeting cards and badges now require a maximum current of several milliamperes with many applications requiring only a few microamperes at about 1.5-3.0 volts. These applications also have the requirement that the power sources be flat and very thin.
In the past twenty-five years, the approach to make thin flat cells/batteries was attempted by numerous scientists, corporations, and approaches. This includes the widely known battery developed by Polaroid. This six-volt battery pack was used in each package of Polaroid film. This allowed Polaroid to have a fresh battery in the camera each time the user placed a new roll of film in the camera. This high cost battery with multiple layers and a metal foil laminate package is a high voltage, high current battery, capable of igniting flash bulbs, and is not a competitor of the new thin low cost batteries that are now being developed. In addition to Polaroid, others have tried to develop thin batteries in various electrochemical systems.
Needed is a way to mass produce an economical, thin battery for use in modern, relatively low-power applications.